Bone treatment systems and methods

Abstract

The present invention relates in certain embodiments to medical devices for treating vertebral compression fractures. More particularly, embodiments of the invention relate to instruments and methods for controllably restoring vertebral body height by controlling the flow of bone cement into the interior of a vertebra and the application of forces causes by the cement flow. An exemplary system utilizes Rf energy in combination a conductive bone cement for selectively polymerizing the inflow plume to increase the viscosity of the cement. In one aspect of the invention, the system utilizes a controller to control bone cement flow parameters to either allow or disallow cement interdigitation into cancellous bone. A method of the invention includes pulsing the flows of bone cement wherein high acceleration of the flow pulses can apply expansion forces across the surface of the cement plume to reduce a vertebral fracture.

What is claimed is: 
     
       1. A system for treating bone, comprising:
 a bone cement injector having a flow channel extending therethrough for injecting bone cement into an interior of a bone, the bone cement injector comprising a metallic shaft having a polymeric layer disposed on an inner surface thereof, the polymeric layer terminating at an end of the metallic shaft, wherein the polymeric layer defines the flow channel and insulates the metallic shaft from the flow channel; 
 an energy emitter coupleable to an energy source and configured to deliver energy to the bone cement to controllably alter the viscosity of the bone cement within the system; and 
 a controller coupleable to the energy source, the controller comprising algorithms for adjusting power delivery applied by the energy source, wherein the controller includes algorithms for adjusting power delivery based on at least one of the following: impedance of the bone cement within the system, temperature of the bone cement within the system, volume of the bone cement within the system, or flow rate of the bone cement within the system. 
 
     
     
       2. The system of  claim 1 , wherein the energy source is at least one of a radiofrequency source, a resistive heat source, a laser source, a microwave source, a magnetic source, or an ultrasound source. 
     
     
       3. The system of  claim 2 , wherein the energy source is a radiofrequency source. 
     
     
       4. The system of  claim 1 , wherein the energy source is a remote energy source. 
     
     
       5. The system of  claim 1 , wherein the controller includes algorithms for adjusting power delivery based on impedance of the bone cement within the system. 
     
     
       6. The system of  claim 1 , wherein the controller includes algorithms for adjusting power delivery based on flow rate of the bone cement within the system. 
     
     
       7. The system of  claim 1 , wherein the controller is configured to adjust power delivery applied by the energy source to alter the bone cement to a viscosity that is sufficient to controllably permeate and interdigitate with cancellous bone. 
     
     
       8. The system of  claim 1 , wherein the polymeric layer is at least one of thermally or electrically insulative. 
     
     
       9. The system of  claim 1 , wherein the polymeric layer comprises a material selected from the group consisting of PEEK (polyetheretherketone), PTFE (polytetrafluoroethylene), Teflon™, and a polyimide. 
     
     
       10. The system of  claim 9 , wherein the polymeric layer comprises PTFE. 
     
     
       11. The system of  claim 1 , wherein the energy emitter is disposed about a distal termination of the flow channel. 
     
     
       12. The system of  claim 1 , wherein the energy emitter comprises one or more electrodes. 
     
     
       13. A system for treating bone, comprising:
 a bone cement injector having a flow channel extending therethrough for injecting bone cement into an interior of a bone, the bone cement injector comprising a metallic shaft having a polymeric layer disposed on an inner surface thereof, the polymeric layer terminating at an end of the metallic shaft, wherein the polymeric layer defines the flow channel and insulates the metallic shaft from the flow channel; 
 an energy emitter coupleable to an energy source and configured to deliver energy to the bone cement as it flows through the system to controllably alter the viscosity of the bone cement within the system; and 
 a controller coupleable to the energy source, the controller comprising algorithms for adjusting power delivery applied by the energy source, wherein the controller is configured to adjust power delivery applied by the energy source to alter the bone cement to a viscosity that is sufficient to controllably permeate and interdigitate with cancellous bone. 
 
     
     
       14. The system of  claim 13 , wherein the energy source is at least one of a radiofrequency source, a resistive heat source, a laser source, a microwave source, a magnetic source, or an ultrasound source. 
     
     
       15. The system of  claim 14 , wherein the energy source is a radiofrequency source. 
     
     
       16. The system of  claim 13 , wherein the polymeric layer is at least one of thermally or electrically insulative. 
     
     
       17. The system of  claim 13 , wherein the polymeric layer comprises a material selected from the group consisting of PEEK (polyetheretherketone), PTFE (polytetrafluoroethylene), Teflon™, and a polyimide. 
     
     
       18. The system of  claim 17 , wherein the polymeric layer comprises PTFE. 
     
     
       19. A system for treating bone, comprising:
 a bone cement injection assembly having a flow channel extending therethrough for injecting bone cement into an interior of a bone, the bone cement injection assembly comprising a metallic shaft having a polymeric layer disposed on an inner surface thereof, the polymeric layer terminating at an end of the metallic shaft, wherein the polymeric layer defines the flow channel and insulates the metallic shaft from the flow channel, wherein the polymeric layer comprises a material selected from the group consisting of PEEK (polyetheretherketone), PTFE (polytetrafluoroethylene), Teflon™, and a polyimide; 
 a source of bone cement operatively coupleable to the flow channel; 
 an energy emitter coupleable to a remote energy source and configured to deliver energy to the bone cement as it flows through the flow channel to controllably alter the viscosity of the bone cement within the flow channel, wherein the energy source is at least one of a radiofrequency source, a resistive heat source, a laser source, a microwave source, a magnetic source, or an ultrasound source; and 
 a controller coupleable to the energy source, the controller comprising algorithms for adjusting power delivery applied by the energy source. 
 
     
     
       20. The system of  claim 19 , wherein the polymeric layer comprises PTFE.